Spin-orbit-induced strong coupling of a single spin to a nanomechanical resonator

TL;DR

This paper theoretically demonstrates that spin-orbit coupling in suspended carbon nanotube quantum dots enables strong coupling between a single electron spin and a nanomechanical resonator, facilitating quantum control and sensing.

Contribution

It introduces a model where spin-orbit interaction induces strong spin-mechanical coupling, enabling quantum electrodynamics phenomena in nanotube-based systems.

Findings

Quantum dot can realize Jaynes-Cummings model in strong-coupling regime

Two distinct qubit subspaces identified at different magnetic fields

Potential for enhanced spin detection and manipulation

Abstract

We theoretically investigate the deflection-induced coupling of an electron spin to vibrational motion due to spin-orbit coupling in suspended carbon nanotube quantum dots. Our estimates indicate that, with current capabilities, a quantum dot with an odd number of electrons can serve as a realization of the Jaynes-Cummings model of quantum electrodynamics in the strong-coupling regime. A quantized flexural mode of the suspended tube plays the role of the optical mode and we identify two distinct two-level subspaces, at small and large magnetic field, which can be used as qubits in this setup. The strong intrinsic spin-mechanical coupling allows for detection, as well as manipulation of the spin qubit, and may yield enhanced performance of nanotubes in sensing applications.